Article enclosing apparatus



1%@ M. E. WALLIS ARTICLE ENCLOSING APPARATUS 4 Sheets-Sheet 1 OriginalFiled Dec.

mii-iillllllli INVENTOR MARVIN E. WALLIS ATTORNEY Nov. 15, 166 M. E.WALLIS ARTICLE ENGLOSING APPARATUS Original Filed Dec. 14, 1961 4Sheets-Sheet 2 \NVE NTOR MARVIN E. WALLIS ATTORNEY Nov. 15, 1966 M. E.WALLIS 3,284,983

ART I CLE ENCLOS ING APPARATUS Original Filed Dec. 14, 1961 4Sheets-Sheet 5 INVENTOR MARVIN E. WALLlS @MWM ATTORNEY Nov. 15, 1966 M.E. WALLIS 3,284,983

ARTICLE ENCLOSING APPARATUS Original Filed Dec. 14, 1961 4 Sheets-Sheet4.

FIG.\7

l N V E N T O R MARVXN E. WALLIS MMTJ J ATTORNEY United States Patent3,284,983 ARTICLE ENCLOSING APPARATUS Marvin E. Wallis, 1643 WoodlandDrive, San Luis Obispo, Calif.

Original application Dec. 14, 1961, Ser. No. 159,355, now Patent No.3,178,866, dated Apr. 20, 1965. Divided and this application Dec. 13,1962, Ser. No. 244,417

1 Claim. (Cl. 53-140) This application is a division of my copendingapplication, Serial No. 159,355, filed December 14, 1961, now Patent No.3,178,866, issued April 20, 1965, which application relates to improvedmeans and methods for packaging various kinds of articles such, forinstance, as those which are presently wrapped in sheet material. Thisdivisional application relates more particularly to an article enclosingapparatus.

Much of the wrapping incident to packaging as practiced today requiresthe making of a sheet of wrapping material, folding it around thearticle, tucking the free ends of the sheet under the article, and thenheat sealing the tucked under ends. Furthermore, the direction of motionof the article is changed at least twice in the operation of manywrapping machines.

It is an important object of the persent invention to make thermoplasticmaterial in film or sheet form and pass an article through the sheet toeffect an enveloping and/or packaging operation without requiring afolding operation and preferably without changing the direction ofmotion of the article.

It is a further object of the invention to provide a downwardly directedfilm or sheet of molten thermoplastic material and move an articlethrough it in such manner as to cause the sheet to wrap around thearticle and form an airtight enclosing adherent wrapping.

It is another object of the invention to move the article by means oftwo conveyors the adjacent ends of which at a wrapping station areseparated by a narrow space through which the aforesaid sheet can passand fall into a tank between successive arrivals of articles at thewrapping station.

Some articles to be wrapped are of such length, or are presented to themachine in such manner, that they cannot conveniently be set obliquelyon the conveyor. In order to establish an oblique relation between thesheet and article it is a further object of the invention to alter thearrangement of the conveyors so that the aforesaid space is oblique withrespect to the path of travel of the article, and also change the angleof the sheet so that it can coat an approaching corner of the article.The unused material can then pass through the space and into the tank.In this way a straight across leading edge of an article can engage thesheet progressively.

It is a further object of the invention to provide a roll to which thesheet will adhere and turn the roll so that it can tension the sheet andalso collect unused material and persent in to doctor blades for returnto the tank.

It is another object of the invention to move the molten material overmeans, such as knife edges, which have the effect of bursting airbubbles to permit escape of the air before it can be entrapped in thematerial in the tank.

Referring again to the oblique space, some articles, such for instanceas slices of bacon, are dropped on a conveyor one by one but will bepackaged in a group. An attempt to lay each slice on the conveyor at anangle but with their ends aligned parallel to the direction of travelwould produce a package of rhomboid form that would not stackeconomically. By using the angular space and sheet the slices can be atright angles to the conveyor and the packages can have right angledcorners ICC so that they can be stacked efliciently. In this connectionit is a further object of the invention to mount the aforesaid roll andaligned pulleys for plural conveyor belts on a rotatable ring or carrierwhich when turned keeps the roll and space parallel to receive theplastic sheet which will be adjusted to have its plane parallel to theroll and space.

It is a still further object of the invention to provide an improvedextruder head made in such manner, as to produce a broad sheet andmounted so as to be adjustable angularly to change the plane of thesheet around horizontal and vertical axes.

The thermoplastic material may be any suitable plastic having thecorrect melt index, viscosity, transparency or color, tensile strength,resistance to passage of air or water, etc. Polyethylene has been usedin the practice of the invention. This material melts at about 350 F.and has a viscosity of about 8000 to 10,000 centiposes and will producea sheet having a thickness from /2 to 1 /2 mils. Other materials whichmay be used include liquid sar-an (polyvinylidene), polyvinyl chlorideif highly plasticized, polypropylene, polystyrene, ethylene copolymers,etc.

In order that the invention may be clearly understood reference is madeto the accompanying drawings which illustrate by way of example oneembodiment of the invention and in which:

FIG. 1 is a plan view of a machine having the invention applied thereto,certain of the parts being broken away and in cross section for the sakeof clarity,

FIG. 2 is a vertical section taken on line 2-2 of i FIG. 1,

FIG. 3 is a transverse vertical section taken on line 3-3, FIG. 1,

FIG. 4 is an end elevational view looking in the direction of arrow 4,FIG. 1,

FIG. 5 is a fragmentary front elevational view looking in the directionof arrow 5, FIG. 1,

FIG. 6 is a sectional view on line 66 of FIG. 3,

FIG. 7 is a cross sectional view of the head and associated parts,

FIG. 8 is a section taken on line 8 8, FIG. 7,

FIGS. 9 and 10 are diagrammatic views of an enlargement of FIG. 8 and aside view thereof respectively,

FIG. 11 is a diagrammatic view illustrating a sheet of the thermolasticmaterial of the form produced in the present invention,

FIG. 12 is a fragmentary view of the upper part of FIG. 6 with certainof the parts being omitted,

FIGS. 13 and 14 are end views looking in the direction of arrows 13 and14 respectively of FIG. 12,

FIG. 15 is a detailed view partly in section of one of the supportingbearings for the conveyor,

FIGS. 16-18 are diagrammatic views showing the method of manufacturingthe head,

FIG. 17 taken as looking in the direction of arrow 17, FIG. 16, and

FIG. 18 is a view taken along line 1818 of FIG. 17. Referringparticularly to FIGS. 1, 2 and 3, the frame F of the machine has legs 10and a table top 11 supports on the legs and has also a shelf 12 whichsupports an electric motor 13 operatively connected to a driving shaft14 journaled on the frame.

Conveyor All the belts 15 pass between a freely rotatable roll 20 and adriving pinch roll 21 connected operatively to shaft 14. When the motor13 is running the rolls cause linear travel of the'belts at a rate whichis adjustable by a rate changer 23 connected operatively between roll 21and the motor.

A stationary vertical guide rod 25 fixed to frame F at 17 and 18 isprovided for each belt and has slidable on it a weighted compensator 26having mounted thereon a freely turning roll 27 under which thecorresponding belt runs. The latter extends upwards and passes over abar 28 and then extends towards the center of the table.

The belt then passes under an adjustably mounted pulley 29 and then overit and to the right over the table. The belt then passes around a guiderod 30 and then goes to the rolls 20 and 21, thus completing itscircuit.

Sub table 35 below table top 11 is mounted on up:

from the seat to open the pipe. Valves of this type are well known.Inlet pipe 73 affords means for introducing fresh plastic material intothe tank to compensate for that used up in the operation of the machine.

The amount of molter thermoplastic material which rises in pipe 66toward the extruding head H is determined by the position of valve 67.If the valve is wide open there will be local circulation in the tank,molten material entering pipe 63, see arrow a, FIGURE 6, going throughthe pump and then through the valve and out of pipe 62, see arrow b.Little or no material reaches the head H under these conditions. If, onthe other hand, valve 67 is partly closed molten material will rise tohead i H to produce a sheet, as will be described. Complete clorights 36and has cross plates 31 and 32 each having a circular opening forbearing 37 in which is rotatable a ring 38. The latter has a horizontalflange 39 formed with arcuate slots 40 through which extend bolts 41which are fastened to the cross plates 31 and 32. When the bolts 41 areloosened the ring 38 can be turned on Z of ring-like shape having innerand outer circular vertical the cross plates to any desired adjustedangular position, after which the bolts can be tightened to hold theadjustment. p

The pulleys 29 are rotatably mounted on bearings 45 adjustable angularlyon the ring. Each hearing has a vertical stud 46 rotatable in a hole 47in ring 38 and a reduced screw .48 on which is threaded a clamp nut 49which engages the underside of the ring and can be tightened to hold thebearing in adjusted angular position. The angular setting of the pulleys29 must be ad justed for any appreciable change in the angular positionof the ring 38 to insure proper running of the belts. The axes of thepulleys should be approximately at right angles to the belts whateverthe position of the ring.

It is to be understood that there are two rows of bearings separatedfrom each other to define an elongated space 50 between them acrosswhich an article to be packaged can be passed from one set of belts tothe other. The normal setting of the belts and pulleys 29 may be assumedto be that in which the crosswise space Stl'is at right angles to thedirection of travel of the belts. When it is desired to make the space50 oblique relative to the belts the ring will be turned and there willbe a vertical motion of the compensators 26, some rising and somefalling. Thus, if the ring is turned to the position shown in FIG. 1 theupper of the belts 15 will move to the left and their compensators 26will rise along their guide rods 25, but the lower belts 15 will move tothe right and their compensators will move down. A correspondingcondition will exist for the belts 16.

Plastic sheet producer The mechanism for making the film or sheet ofthermoplastic material includes a tank and heater to supply the moltenmaterial, an extruder head to discharge the sheet downwardly across thepath traversed by the article to be packaged, provision for tensioningthe sheet, and means to return the unused material to the tank.

Referring to FIGURE 6, there is shown a wall 55 enclosing a tank 56having inner and outer shells 57 and 58, respectively, and bottoms 59and 60 for confining heated oil. The oil can be heated in any approvedmannor, as by electric heater 61. The jacket is entered by upper andlower pipes 62 and 63 respectively, the latter of which leads to a pump64 belt driven by a motor 65. Leading upwardly from the pump is a pipe66 which is connected to pipe 62 and continues upwardly as shown inFIGURE 6. Pipe 62 has therein a valve 67 controllable from above thejacket by rod 68 and hand grip 69. The valve has a conical seat 70secured to pipe 62 and a valve head 71 which by turning rod 68 can bemoved into the seat to close pipe 62, or be moved away sure of valve 67will effect delivery of molten material to head H under full pressure ofthe pump 64. Full pressure can be varied by changing the speed of motor65, or in any manner which will change the operating conditions of thepump. During heating of the thermoplastic material up to operatingtemperature, or under other nonoperati-ng conditions, the pump will beidle, or be operated slowly with valve 67 Wide open.

Secured within the upper part of the tank is a well 75 walls 76 and 77jointed by a bottom 78. The outer wall 77 is secured to inner wall 56 ofthe tank and the upper edge of the inner wall 76 is sharpened to a knifeedge 79.

. A hollow cone 80 is placed as shown in FIGURE 6 and is held inposition by feet 81 which are fastened to the inner part of the cone andto the floor 78 of the well. The knife edge 79 is lower than the top 82of the tank and the bottom of the cone extends below the level ofmaterial normally in the well. The cone 80 serves as a deflector forhardened resin falling from above and requires the resin to move intothe well and prevents it from falling into the tank.

The extruding head H is shown in FIGURES 7-10 and 16-l8. The upper end85 of pipe 66 has internal screw threads 86 which receive the screwthreaded nipple 87 of a clamp member 88 having a concave sphericalsurface 89 into which fits a hollow ball 90. A passage 91 through theball is screw threaded to receive the externally thread- 2 ed end ofbody 72 forming part of head H. A second clamp member 93 also has aconcave spherical surface to [fit the ball, and bolts or screws 95 clampthe members 88 and 93 together tightly to provide a tight leak-proofadjustable connection between pipe and body 72. The ball permits limiteduniversal adjustment of the body 72 to accommodate the latter to avariety of operating conditions.

The body 72 has a cavity 96 from which leads a short small passage 97.The end of cavity 96 is cone-shaped as at 98 to cause the molten plasticmaterial under pressure to move toward the passage 97. A transverseoblique slot communicates with passage 97 and extends downwardly and isinclined rearwardly or in a direction the opposite to that in which themolten material approaches passage 97, as viewed in FIG. 7.

FIGURE 8 shows a significant feature of the slot 100. The transverseareas 101 which define the upper configruration of the interior of slot100 are at an angle A to each other less than 180, preferably about andthis angle is bisected by a vertical line g1 passing through the axis ofpassage 97. The vertex of this angle is indicated at 99 in FIGURE 9. Theangle between the slot 100 and the axis of body 72 as viewed in FIGURE 7is about 60. This angle in cooperation with surfaces 101 requires someat least of the molten plastic material to reverse its direction of flowand emerge from slot 100 in a generally left-hand direction as shown inFIG. 7.

FIGURES 9 and 10 show diagrammatically an enlargement of FIGURE 8 and anenlarged side view of FIGURE 8, respectively. FIGURE 11 shows anelevation of a sheet of thermoplastic material of the form produced bythe present invention. In FIGURE 9 line d-e passes horizontally throughthe small circle 1 representing the stream of molten material in passage97. Vertical line fg intersects the circle of the body at h, and lined-e intersects the circle at k and n. The lines ]p and is represent theupper transverse limiting edges 101 of the slot 100. The lowest point ofthe slot is represented at w in FIGURES 9 and 10.

Tension of plastic sheet The head H, which defines in general the localeof extrusion of the film, is adjusted so that the film or sheet SH ofmolten thermoplastic material can be directed into the space 50 betweenthe ends of the belts 15 and 16. Directly under this space there ismounted a roll 110 which turns below the belts 15 and 16 but above thecone 80. As shown in FIGURES 1 and 12, this roll is mounted for rotationin bearings 111 and 112 depending from ring 38. The axis of the roll isparallel to the length of space 50 and the roll has a shaft 113 to whichis connected a driver 114. The latter is supported on a bracket 115secured to bearing 111 and includes a motor 116 and a gear reducer 117driven by it and connected to shaft 113.

The rate at which roll 110 turns is such that its peripheral speed willbe somewhat more than the rate of travel of sheet SH toward it. Becauseof this relation in rates the sheet will be under some tension whichtends to orient the particles of which the sheet is made, and also tendsto make the sheet transparent. The roll is able to tension the sheet SHdue to the fact that the latter is adhesive and sticks to thecylindrical surface of the roll. The periphery of the roll can beconsidered to be a traveling surface, and the roll acts as a draft meanson the film.

In order to remove the plastic material which accumulates on the rollthere are provided scraper or doctor blades shown in FIGURES 12-14. Aprimary blade 120 is held in place on small supports 121, one for eachof the bearings 111 and 112. The upper edge of this blade does notnormally touch the roll but is spaced from it slightly so as to cut offthe outer part of the accumulated plastic. The remainder of the plasticis removed by a secondary blade 122 which is mounted on supports 123 secured to bearings 111 and 112 similarly to blade 120 and supports 121.This second blade is set closer to the roll than is blade 120 andnormally engages the roll to scrape off all the remaining plasticmaterial. A guide plate 125 mounted as shown close to the secondaryblade directs material removed by it to the left-hand side of the cone80 as viewed in FIGURE 12.

The plastic material which is scraped from roll 110 falls on cone 80 andthen moves into the well 75. The level of molten material in the tank ismaintained high enough, as at line 130, so that its heat will keep thematerial in the well fluid and enable it to melt material entering thewell from the cone. As material falls into the well it carries airbubbles with it and also causes the molten material already in the wellto flow over air releasing knife edge 79 and into the tank, which is areceiver for air-free resin. A vent 131 in the top of cone S preventsformation of an air trap which would otherwise interfere with passage ofmaterial from the well over edge 79.

FIGURES 6, 13 and 14 show shields which serve to prevent the plasticsheet from getting onto the belts and 16, thus protecting the latterfrom undesired accumulation of resin. The right and left-hand shields135 and 1.3-6 respectively are sup-ported from the bearings 111 and 112.FIGURE 13 shows one end of shield 136 but it is to be understood thatthe opposite end is the same except of the opposite hand. Likewise,FIGURE 14 shows only one end of shield 135, but it will be understoodthat the other end is the same except of opposite hand.

The lower edge 137 of shield 136 is fastened at 138 to the bearings 111and 112, bearing 112 only being shown in FIGURE 13, and the upper edge139 of shield 136 extends through a slot 140 in ring 38. Similarly, thelower edge 141 of shield is fastened at 142 to the bearings 111 and 112,bearing 111 only being shown in FIGURE 14, and the upper edge 143 ofshield 135 projects up through slot The upper edges of the shields areoppositely curved at 145 as shown in FIGURE 6 to partly at least enclosethe adjacent ends of the belts 15 and 16. The previously mentioned space50 is defined by the curved edges 145. The lengthwise centerline of thisslot is slightly to the right ofa vertical plane passing through theaxis of roll 110.

Returning to the extruding head H, part of the method of its manufactureis shown in FIGURES 16-18. These figures are enlarged views showingdiagrammatically how the drilling and slot cutting operations are done.The passage 97 is made by a drill the cutting edges of which are at anoblique angle to the drill axis and leave a concave cone indicated inFIGURE 16. The elements of the cone, as 151, are at about 60 to the axisof passage 97.

Slot 100 is then cut at an angle of about 60 to the axis of passage 97to a depth of slightly more than half the diameter of body 72. Theleft-hand side 152 (FIG- URE 16) of the slot cuts across the concavecone about as shown in FIGURE 16 at some such point as 153 on element151. The height of slot 100 at this point in the process is indicated byline 154. Then by two subsequent cutting operations slot 100 is extendedobliquely upwardly on each side of the center line g to form the sidesor walls 101 already mentioned. Cutting of the slot removes the lowerpart of the concave cone and cut back somewhat into the cylindrical partof passage 97, as at 155.

At the upper part of the right-hand end (FIGURE 18) of passage 97 thereis a surface 156 inclined downwardly and away from the open end ofcavity 96, being the remainder of the concave cone already mentioned. Itserves to deflect downwardly into slot 100 molten plastic materialmoving out of the passage 97. The surfaces 101 (FIGURE 17) define theupper internal boundaries of slot 100 and form angle A against which thedownwardly deflected material impinges. The walls 101 serve to deflectlaterally molten material moving toward them. These downward and lateraldeflections co bine to give the film or sheet SH the form shown inFIGURE 11. The axis of the conical surface coincides with the axis ofbore 97 and extends across slot 100.

The body 72 is preferably cylindrical and due to the angle of slot 100the distance from the central axis of body 72 to the surface of thelatter, measured along slot 100 to point w, is greater than the distancemeasured horizontally. Since slot 100 has parallel sides more resistanceis offered to movement of resin to point w than to points k and n andthis difference compensates for the fact that the shorter central partof the film, FIGURE 11, requires less material than does the outercurved part.

It is believed that the operation of the machine will be apparent fromthe foregoing description. After the plastic material has reached itsproper temperature, such for instance as 350", and the pump has been setin operation to develop a pressure ranging from 250 p.s.i. to 1000 psi,and valve 67 closed, a liquid film of the plastic material will issuefrom the slot 100 and be projected downwardly toward the slot 50. If thearticle to be coated is comparatively small and can be set obliquely ordiagonally on the conveyors, it may be set in that position and the slot50 will then be at right angle to the direction of travel, but if forany reason the article is too long or is presented to the conveyor beltsin such manner as to require that the angle of the sheet be changed,then the ring can be adjusted to the desired angle. The angle of theextruding head H will be adjusted to conform to that of the slot 50.During the adjustment of the conveyor the weighted compensators willeither rise or fall,

as the case may 7 be, so that all of the belts well be kept taut.

the sheet and as the article continues to move part at transferred frombelts 16 to belts 15.

As the film leaves the top of the package it will follow down along thetrailing end of the package and upon reaching the bottom of the packagewill break away from the latter and reestablish its contact withthe'roll before the next article arrives. If the package is placed onthe conveyor obliquely With a corner leading then the top and two sideswill be enveloped by a single pass and a second pass, with the packagereversed and inverted, will complete the operation.

As the machine continues to run some of the resin or plastic materialall accumulate on roll 110 and will be removed and fall mto the wellwhere it will be melted sufiiciently to pass over the knife edge 79 ofthe well. This edge Will have the elfect of requiring the moltenmaterial to become very thin and bend down at a sharp angle so that anybubbles or air accumulations in the resin Will in all likelihood burstso that upon arrival at the tank the material Will be substantially freefrom occluded air.

Reference to FIGURE 11 will call attention to another feature of theinvention. Prior to arrival of an article M at the film SH the latterWill be a continuous sheet connected adhesively for its full width toroll 110. When the article M moves into the film the latter will beinterrupted for the Width of the article, as for instance for the spacex and the film will lose its contact with roll 110 for this portion ofits width. The parts y of the film beyond, or at the sides of, space xwill, however, remain in contact with the roll, and as the articleleaves the film these parts, still connected to the upper part of thefilm, will draw the intermediate part of the film back to the roll.

The invention is not limited to the specific matter already described.Thus, the resin in the tank can be heated in any approved manner andappropriate electric circuitry can be employed for the various drivesand heaters. Pressure gauge and thermometer means are used where needed.Pipes 66 and 85 can be enclosed in heat insula tion jackets, heated ifof articles can be enveloped, those of rectangular form enveloped canalso of the film.

Having now particularly described and ascertained the nature of theinvention and in what manner the same is to be performed, what isclaimed is:

i In an article packaging machine,

(b) means to project a resin from above said space,

(0) means eifective to move said article carried by one of them otherconveyor,

((1) a ring rotatable on the machine in part supporting said conveyorsand operative upon rotation of the ring to change the angle ofseparation between the References Cited by the Examiner UNITED STATESPATENTS 10/ 1949 Farrell 12/ 1953 Clement 11/1954 Okawa et al. 10/196'2Norman et al 4/ 1965 Wallis FRANK E. BAIL'EY, Primary Examiner.

TRAVIS S. MCGEHEE, Examiner. 50 A. E. FOURNIER, P. H. POHL, AssistantExaminers.

conveyors to cause an to pass at least part- Way through said sheet andbe transferred to the 53-140 53-123 X 182 X 99-171 X 53-140

